On Mon, 2005-12-12 at 18:19 +0100, Herbert Poetzl wrote: > On Mon, Dec 12, 2005 at 07:13:46PM +0200, Roché Compaan wrote: > > On Mon, 2005-12-12 at 16:53 +0100, Herbert Poetzl wrote: > > > On Mon, Dec 12, 2005 at 03:34:13PM +0200, Roché Compaan wrote: > > > > On Mon, 2005-12-12 at 03:06 +0100, Herbert Poetzl wrote: > > > > > On Sun, Dec 11, 2005 at 10:28:04PM +0200, Roché Compaan wrote: > > > > > > On Sun, 2005-12-11 at 11:34 -0800, Alexander Kabanov wrote: > > > > > > > hi, > > > > > > > > > > > > > > i'm having similar errors (I do have limits and scheduler set, > > > > > > > using > > > > > > > rlimits (as, rss, nproc) and scheduler) whenever i do stress > > > > > > > testing, > > > > > > > (overloading mta or web server for example). > > > > > > > > > > > > > > during a stress test, some applications die because of no memory > > > > > > > available or can't fork, some stop with segmentation fault (not > > > > > > > able > > > > > > > to do vserver <vs> enter),. when attacking httpd might have httpd > > > > > > > <defunct>. > > > > > > > > > > > > I am experiencing the same problems. The segfaults and not being > > > > > > able to > > > > > > enter a vserver from the host *really* worries me. > > > > > > > > > > well, if the limits are reached, the guest can not create > > > > > new processes and/or instantiate more memory ... of course > > > > > this might lead to program termination and the fact that > > > > > a guest cannot be entered (as the limits are hard limits). > > > > > raising them will make it all work again ... > > > > > > > > If the vserver is hitting the limit then I'm less worried because I > > > > can solve the problem by increasing the limit. I misread and thought > > > > that there was plenty of memory to spare. > > > > > > > > Would I be right in assuming that increasing only the virtual memory > > > > will solve the problem? > > > > > > probably that will solve 80% of the issues > > > (see VM vs RSS hit ratio) > > > > Where? > > in the original email you sent (you removed the > lines so I could not refer to them ...)
Ah, thanks. > > > > > I don't mind if virtual servers use swap space if they need memory > > > > because we have plenty of disk space, but I don't want them to > > > > consume all the physical memory on the box. > > > > > > trust me, you do mind as soon as the guests start > > > swapping in and out ... > > > > Sorry, you'll have to explain - I don't understand how the vserver or > > the linux kernel manages virtual memory or what you mean when you say > > "swapping in and out". > > consider a total of 256 MB memory (RAM) on the host > further, consider three guests with a memory footprint > of 128MB RSS (means they need to have 128MB in memory > to run, that's what Resident Set Size is), now they > are alternating and will constantly swap in and out > memory, because 3*128 > 256 ... But what if I limit the sum of virtual server RSS limits to never exceed the total RAM on the host as a rule, and make sure that there is enough virtual memory for all of them? Ie. I have 4 GB RAM on the host and 4 vservers that each have a hard limit of 1 GB RSS and say triple the virtual memory. Would I still get memory errors when vservers reach the RSS limit, or only when they reach the VM limit? -- Roché Compaan Upfront Systems http://www.upfrontsystems.co.za _______________________________________________ Vserver mailing list [email protected] http://list.linux-vserver.org/mailman/listinfo/vserver
